1. Field of the Invention
The present invention relates to a multi chip package for fixing each chip by a paste.
2. Description of the Related Art
FIG. 1 is a schematic diagram of the conventional multi chip package.
In FIG. 1, a first semiconductor chip 103 is mounted on the die pad 101. A second semiconductor chip 104 is mounted on the first semiconductor chip 103. The second semiconductor chip 104 is fixed to the top surface of the first semiconductor chip 103 using an adhesive tape 105. The adhesive tape 105 is made by an insulating material. A plurality of leads 102 are located around the die pad 101. The leads 102 are electrically connected to the semiconductor chips 103 and 104 through conductive lines. The die pad 101 and the first and second semiconductor chips 103 and 104 are encapsulated by a sealing resin 106.
In the conventional multi chip package, each of the semiconductor chips is usually adhered by the insulating tape. As shown in FIG. 1, the adhesive tape 105 is attached to the entire back surface of the second semiconductor chip 104. Therefore, the second semiconductor chip 104 is fixed to the first semiconductor chip 103 strongly and also the second semiconductor chip 104 does not tilt.
However, the adhesive tape 105 is expensive. Therefore, various pastes are used as an adhesive material instead of the insulating tape.
FIG. 2 is a schematic diagram of the multi chip package using an adhesive paste.
In FIG. 2, a first semiconductor chip 203 is mounted on a die pad 201. A second semiconductor chip 204 is mounted on the first semiconductor chip 203. The second semiconductor chip 204 is fixed to a top surface of the first semiconductor chip 203 using an adhesive paste 205. A plurality of leads 202 are located around the die pad 201. The leads 202 are electrically connected to the semiconductor chips 203 and 204. The die pad 201 and the first and second semiconductor chips 203 and 204 are sealed by a sealing resin 206.
Such multi chip package is described in Japanese Laid-Open Patent No. Shou 63(1988)-55943 or Japanese Laid-Open Patent No. 2000-340934.
Since the adhesive paste 205 is fluid resin, the first semiconductor chip 203 is easy to tilt. When the first semiconductor chip 203 tilts heavily, the first semiconductor chip 203 might touch the surface of the second semiconductor chip 204 as shown in FIG. 3.
Further, it is difficult to form the paste evenly on the first semiconductor chip 203.
Accordingly, in an object of the present invention, a multi chip package for decreasing the tilt of the semiconductor chip is provided.